The present invention relates to a method and apparatus for manufacturing a unidirectional reinforced resin structure, and more particularly, to a method and apparatus for manufacturing a thermoplastic resin structure which is reinforced by impregnating unidirectionally arranged continuous long fibers with a melt thermoplastic resin. Further, it is to be noted that the term "unidirectionally reinforced resin structure" used herein means a resin structure formed of continuous long fiber bundles which are arranged unidirectionally and reinforced by being impregnated with a melt resin.
Known methods and apparatuses of the kind mentioned below have been disclosed in, for example, Japanese Patent Publication No. SHO 63-37694, Japanese Patent Laid-open Publication No. SHO 63-264326, Japanese Patent Publication No. HEI 5-68327 and WO Publication No. 97-19805.
In the known art of Japanese Patent Publication No. SHO 63-37694, there is disclosed a method of impregnating and reinforcing a long fiber bundle with a melt resin by passing it under tension along a surface of a spreader while contacting the spreader.
Further, in the known art of Japanese Patent Laid-open Publication No. SHO 63-264326, there is disclosed a method in which fiber bundles are spread into a web shape (i.e., band shape). The web is then coated with a melt resin, and thereafter, impregnated with the melt resin during the passing thereof in a specified barrier layer while contacting the barrier. The specified barrier layer is arranged in a zigzag shape in an impregnation die.
In the known art of the Japanese Patent Publication No. HEI 5-68327, there is disclosed a method in which a melt resin is extruded from a tip end of an arc-shaped head of an extruder. At the same time, fiber bundles applied under tension are passed in contact with the arc-shaped head. Thus, impregnation is performed.
In the known art of WO Publication No. 97-19805, there is disclosed a method in which continuous fiber bundles to be reinforced are impregnated by passing between a pair of opening pins disposed in an impregnation die while not contacting the pins.
According to the various methods mentioned above, unidirectionally reinforced resin structures having improved impregnated conditions are obtainable.
However, in the case where the number of reinforcing fiber bundles are scaled-up (for example), a manufacturing apparatus having large structure must be used. This results in a problem of increasing manufacturing costs for the reinforced resin structure, and in addition, the workability (operability) at the time of manufacturing of the unidirectional reinforced resin structure is made extremely worse. This happens because it is important and significant to make a sufficiently wide reinforcing fiber bundle to achieve an improved impregnated condition regardless of the opening impregnation method.